Improvement in the manufacture of artificial stone



signs, &c., and by varying the proportions as UNITED STATES PATENT OFFICE,

ANDREW J. CRAWFORD, OF BROOKLYN, NEW YORK, ASSIGNOR TO HIMSELF, WILLIAM H. STONE, OF ST. LOUIS, MISSOURI, 'JOSEPH H. LIVINGSTON AND JAMES D. WELOH, OF PHILADELPHIA, PENNSYLVANIA, AND HENRY S. HAWKS AND ROBERT A. FISHE R, OF NEW YORK CITY.

u IMPROVEMENT IN THE MANUFACTURE OF ARTIFICIAL STONE.

Specification forming part of Letters Patent No. 128,365, dated June 25, 1872.

To all whom it may concern:

Be it known that I, ANDREW J. CRAWFORD, of Brooklyn, in the county of Kings and State of New York, have invented a new and useful Improvement in the Manufacture of Artificial Stone, tobe known as Orawfords Excelsior Artificial Stone, of which the following is a specification:

This invention has for its object the prime tion of a composition of matter which, afgerflo id of i having set or become indurated, will p take in its nature of the natural-stone formations-that is to say, it will have a hard surface, not easily abraded, and not afl'ected by atmospheric influences, and the mass will be capable of resisting in an eminent degree either a crushing or tensile force. This composition, while plastic, can be molded into any shape desired, for building-blocks, ornamental dehereinafter specified can be employed for the formation of tiles or the laying of pavements in sections or continuous lengths. It consists in a due and proper admixture of any of the hydraulic cements, under which head are enumerate uzzo ana Portland, Roman, Louisvi e, Rosendale ail other we nown ce ments, the solidification of which depends upon the combination of lime with silica and alumina, forming first a hydrate and finally a silicate, together with sand, gravel, or broken stone, pulverized limestone, x1 e of iron, and silicate of sgda or pofassa, 1n proportions about as ereiuafter enumera ed for the formation of the plastic mass; and, further, in the f nishing treatment, by the use of agashpg cdatinfg'fi'or'iiiewbydissolving alum in water -5iust ni *earenu sum thereiilfilrylng tirenaswnu sub, acting it to heat, and finally forming a paste therefrom to be applied to such articles as are molded from the plastic mass and require a polished surface.

It is here stated that wherever, in the followin g list of ingredients, the word cement is used one of the before-mentioned cements is intended, always giving the preference to Portland cement, the weight of which shall average I el; and wherever other cements are used the relative proportions of the ingredients should be modified to allow for the inferiority of the cement.

, QL1.LQ weight rests, take, by measure- Portland cement parts. Sand 80 Pulverized limestone 80 Alkaline silicate 5 Total 200 For blocks used in buildings, and which are 15 parts. Gravel, broken stone, pebbles, or

similar material Pulverized limestone 35 Oxide of iron v 15 @lkalinc silicate. 5

Total 200 For sidewalks, paving, 850., a necessary quality of which is that its surface shall not abrade, or wear off easily, take, by measure- Cement 8 parts. Sand 32 Gravel, broken stones, or similar material 128 Pulverized limestone 24 Oxide of iron 7 ,Alkaliue silicate 1 Total ..-....'......200-

W a Second intermix g" a 'esiflailel a ter which the kaline silicate is introduced together with the smallest amount of wate which will bring the materials to a pl astic condition. The mass is then thoroughly worked one hundred and twenty pounds to the bushuntil it exhibits a homogenous condition, when For moldings, stucco, 860., upon which little n 0. as;

miner it is ready to be molded into the form desired or used in the laying of walks, 8w.

Where a building-block is the purpose intended, or the molded articles require a smooth polished surface, it is obtained in the followin g manner: Mix seventy-five or eightypounds of ca1cinedgyps%m with two gallons of water in which a poun "o'f sul hate of iron or o 55 yetameisn r ieta an one an m oilalum have been previously dissolved, dry the mass by exposure to the air for one day, and calcine at a dull red heat or by exposure to the open air. e pow'der, thus prepared, is formed into a thick aste with water and the surface of the art1c e ruslid'bfcoated therewith, and finally finish by polishing with emery, pumice-stone, or in any of the wellknown ways.

Having thus described 'my invention, what Iclaim, and desire to secure by Letters Patcut, is-

The artificial stone herein described, called Orawfords Excelsior Artificial Stone, and com posed of a hydraulic cement, together with sand, gravel, or broken stone, pulverized limestone, oxide of iron, and an alkaline silicate, about in the proportions specified, to be used for pavements, sidewalks, building-blocks, &c.

In testimony that I claim the foregoing I have hereunto signed my name this 6th day of June, 1872.

A. J. CRAWFORD.

Witnesses:

H. S. DAVIS, J. H. JOHNSTON. 

